Bumper extension



FIG. 1 is a bottom front perspective view of the outside of a bumper extension showing my new design;

FIG. 2 is a top front perspective view of the outside thereof;

FIG. 3 is a top rear perspective view of the inside thereof; and

FIG. 4 is a bottom rear perspective view of the inside thereof. 

The ornamental design for a bumper extension, as shown. 